As a Grandma bringing up my two Grandaughters and teenagers at that! I have been faced with challenges that would have drove the patients of a saint. Don't let this remark shadow how discipline needs to be applied. For me personally being consistant is important ,there is no room for a discusion on the punishment given, if they want to challange this then they realise that another punishment will be set.I also know it's so important they understand why they are being punished,explaining helps as it builds good relationships between parent and child. Tell them you love them every single day, hugs and love are the key, listening another good tool just takes practice. Spankins are never a positive way of correcting bad behaviour. I use the sandwhich method which is starting positive, i e thank you for making me that coffee, then the negative which is saying but next time you make one would you please clean up the mess. Thirdly end on a positive and this could be by saying , i really enjoyed that coffee it was tasty.I'm not saying i am right, just sharing some of my experiences and what works for me.